The present inventive concept herein relates to a semiconductor memory device, and more particularly, to a nonvolatile memory device.
Semiconductor devices are memory devices fabricated from semiconductor material such as silicon, germanium, gallium arsenide and indium phospide. Semiconductor memory devices are generally classified as either volatile memory devices or nonvolatile memory devices.
Volatile memory devices lose their stored data when the supply of power is interrupted, and examples thereof include static random access memory (SRAM), dynamic RAM (DRAM), and synchronous DRAM (SDRAM). On the other hand, nonvolatile memory devices retain their stored data even when the supply of power is interrupted. Examples of nonvolatile memory devices include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM), flash memory, phase change RAM (PRAM), magnetic RAM (MRAM), resistive RAM (RRAM), and ferroelectric RAM (FRAM).